From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from fg-out-1718.google.com ([72.14.220.152]:35927 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751485Ab0FFRv6 (ORCPT ); Sun, 6 Jun 2010 13:51:58 -0400 Message-ID: <4C0BE03C.8000709@gmail.com> Date: Sun, 06 Jun 2010 19:51:56 +0200 From: Jiri Slaby MIME-Version: 1.0 To: Richard Zidlicky CC: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH 2.6.34] schedule inside spin_lock_irqsave References: <20100530145240.GA21559@linux-m68k.org> <4C028336.8030704@gmail.com> <20100606124302.GA10119@linux-m68k.org> In-Reply-To: <20100606124302.GA10119@linux-m68k.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 06/06/2010 02:43 PM, Richard Zidlicky wrote: > Hi, > > I have done a minimaly invasive patch for the stable 2.6.34 kernel and stress-tested > it for many hours, definitely seems to improve the behaviour. > > I have left out your beautification suggestion for now, want to do more playing with > other aspects of the driver. There still seem to be issues when the device is unplugged > while in use and such. > > --- linux-2.6.34/drivers/media/dvb/siano/smscoreapi.c.rz 2010-06-03 21:58:11.000000000 +0200 > +++ linux-2.6.34/drivers/media/dvb/siano/smscoreapi.c 2010-06-04 23:00:35.000000000 +0200 > @@ -1100,31 +1100,26 @@ > * > * @return pointer to descriptor on success, NULL on error. > */ > -struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) > + > +struct smscore_buffer_t *get_entry(void) > { > struct smscore_buffer_t *cb = NULL; > unsigned long flags; > > - DEFINE_WAIT(wait); > - > spin_lock_irqsave(&coredev->bufferslock, flags); Sorry, maybe I'm just blind, but where is 'coredev' defined in this scope? You probably forgot to pass it to get_entry? How could this be compiled? Is there coredev defined globally? > - > - /* This function must return a valid buffer, since the buffer list is > - * finite, we check that there is an available buffer, if not, we wait > - * until such buffer become available. > - */ > - > - prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE); > - > - if (list_empty(&coredev->buffers)) > - schedule(); > - > - finish_wait(&coredev->buffer_mng_waitq, &wait); > - > + if (!list_empty(&coredev->buffers)) { > cb = (struct smscore_buffer_t *) coredev->buffers.next; > list_del(&cb->entry); > - > + } > spin_unlock_irqrestore(&coredev->bufferslock, flags); > + return cb; > +} > + > +struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) > +{ > + struct smscore_buffer_t *cb = NULL; > + > + wait_event(coredev->buffer_mng_waitq, (cb = get_entry())); > > return cb; > } -- js